Treatment of tar



Patented Apr. 1929.

UNITED STATES PATENT OFFICE.

OBIN 1D CUNNINGHAM; OF INDIANAPOLIS, INDIANA, ASSIGNOR T0 IETER REILLY, OF INDIANAPOLIS, INDIANA.

I Tmmn'r or man.

No Drawing.

- The present invention relates to the treatl process involves thevintimate incorporation of coal tar with sulfuric acid while in a coolcondition, and the subsequent heating of the mixture sufliciently to effect sulfonation of the tarry material, which sulfonation should be as complete as possible. Any kind of tars can be-used, e. g. tars of mineral (organic) animal or vegetablesources.

As a preferred example, I cite the treatment of a coal tar: 1 part of common coal tar is, emulsified with about 5 parts of strong sulfuric acid, at room temperature.

If the tar shows a considerable tendency to heat up on mixing with the acid, it is preferable to employ artificial cooling in this step.

' The mixture is then heated to about 160 or 170 (1., care being taken to prevent excessive foaming, particularly during the early stages and at the end of the treatment.

The sulfonated product is then dumped into a large quantity of water and is washed several times by decantation with water to remove the excess acid. This product can then be dried if desired, but it is preferably notdried beyond the stage of a paste. The water might thereafter be displaced by another solvent, in knownmanner.

The solid matter in the paste, is a black impalpable powder which can readily be separated from a large bulk of water or aqueous liquids by decantation.

This product has decolorizing properties in this form.

When using this as a decolorizing agent, acid is liberated, (sulfuric acid being a product of the decolorizing reaction). This would be suitable for decolorizing a glucose solution. If the product is treated with an alkali the decolorizing properties are lost, but the product would st-illbe useful as a substitute for carbon black, i. e., as a filler for rubber compositions or as a pigment.

The treatment with alkaline solutions removes a substantial fraction of the product Application filed April 27, 1925/ SeriaI'No. 26,301.-

may be concentrated to the stage of a paste.

The water in this paste maybe displaced by organlc solvents, in the well known manner.

The product after the alkali treatment, while in the form of a paste, is very smooth and fine textured and can be spread as a smooth adherent film on paper or other like surface. 1

' Reference was made above to the possibility of drying the product from the sulfonation and washing process. It is better to use it in the paste form. Generally drymg causes the product to set to a cake which is too hard'to crush between the fingers and is difli'cult to grind to its original state of fineness.

In mixing the acid with the tar, it is important that the mixing be effected cold and that the mixing be thorough to produce satisfactory results. If the mixing is conducted hot, a gummy. mass is likely to be produced, which cannot be completely incorporated with the acid.

Other tars Will be treated in substantially the same manner as above.

I claim 1. That method of treating tar for the production of a material suitable as a base to be employed as a filler or pigment or for decolorizing material which comprises admixing tar with more than its own weight .of cold sulphuric acid, and thereafter heating the mixture to effect sulphonation.

2. That method of treating coal tar for the production of a material suitable as a base to be employed as a filler or pigment or for decolorizing material which consists in admixing coal tar with cold sulphuric acid, heating the mixture to effect sulphonation, and thereafter running the sulphonated mass into a body of water.

3 That method of treating coal tar for the production of a material suitable as a base to be employed as a filler or pigment or for decolorizing material which consists in admixing tar with cold sulphuric acid, heating the mixture to effect sulpho'na ion,

thereafter running the sulphonated' into a body of water, separating the mass, and subjecting the mass to a washing =action. i

5 4. That method of treating coal tar for the production of a material suitable tobe I employed as a filler or pigment which consists in admixing phuric acid; heating the admixture until sulphonation is effected; washing the mass' and neutralizing the same. a 5. In the art of treating tar, the herein described step which comprises thoroughly coal tar with cold sul-- mixing tar with several times its own weight of strong sulfuric acid and there- 1} after heating until sulfonation is efiected.

6. Completely sulfonated tar.

7. Completely sulfonated coal ta.

8. Sulfonated tar having d'ecolorizing properties.

9. Sulfonated tar having dlecolol'izing properties which are lost in treatment-with alkali,

In testimony whereof I have slgned my name to this specification.

ORIN D. CUNNINGHAM. 

